Answer:
-4.0 N
Explanation:
Since the force of friction is the only force acting on the box, according to Newton's second law its magnitude must be equal to the product between mass (m) and acceleration (a):
(1)
We can find the mass of the box from its weight: in fact, since the weight is W = 50.0 N, its mass will be
And we can fidn the acceleration by using the formula:
where
v = 0 is the final velocity
u = 1.75 m/s is the initial velocity
t = 2.25 s is the time the box needs to stop
Substituting, we find
(the acceleration is negative since it is opposite to the motion, so it is a deceleration)
Therefore, substituting into eq.(1) we find the force of friction:
Where the negative sign means the direction of the force is opposite to the motion of the box.
If it is completely elastic, you can calculate the velocity of the second ball from the kinetic energy
<span>v1 = velocity of #1 </span>
<span>v1' = velocity of #1 after collision </span>
<span>v2' = velocity of #2 after collision. </span>
<span>kinetic energy: v1^2 = v1' ^2 + v2' ^2 (1/2 and m cancel out) </span>
<span>5^2 = 4.35^2 + v2' ^2 </span>
<span>v2 = 2.46 m/s <--- ANSWER</span>
Answer:
V=22.4m/s;T=2.29s
Explanation:
We will use two formulas in order to solve this problem. To determine the velocity at the bottom we can use potential and kinetic energy to solve for the velocity and use the uniformly accelerated displacement formula:
Solving for velocity using equation 1:
Solving for time in equation 2:
Answer:
56250 N
Explanation:
mass, m = 6000 kg
initial speed, u = 20 m/s
final speed, v = 5 m/s
distance, s = 20 m
Use third equation of motion
5 x 5 = 20 x 20 + 2 a x 20
25 = 400 + 40 a
a = - 9.375 m/s^2
Braking force, F = mass x acceleration
F = 6000 x 9.375
F = 56250 N
<span>B). it will decrease.
But, you should keep the temperature constant, 'cause according to Boyle's law, pressure of the ideal gases is indirectly proportional to it's volume but at constant temperature. So, don't confuse in that.
Hope this helps!
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